The present invention relates to an optical disk apparatus for recording/reproducing information onto/from an optical disk, and in particular, it relates to an optical disk apparatus having the structures being suitable for reducing noises accompanying rotation of the disk at high speed.
For example, an optical disk apparatus for recording and/or reproducing data onto/from an optical disk, being a disk-like optical information recording medium, such as, a CD or DVD, etc., is widely applied to be a data recording/reproducing apparatus for data of digital audio and/or digital moving picture, or an internal or external memory device of a personal computer, for example, because of the distinctive characteristics thereof, i.e., being non-contact, having a large capacity and being low of a cost thereof, and enabling data access at high speed.
With such the optical disk apparatus for performing the recording/reproducing onto/from the CD-ROM and DVD, in particular in the recent years, it is in a tendency of increasing the memory capacity thereof, more and more, accompanying the development made upon technologies for recoding/reproducing the optical disk. For that reason, requirement is also made upon the optical disk apparatus having disk rotation speed, being faster much more. In more details thereof, at present are already available on the market the followings; i.e., having a ten-speed (10×) (2,200 rpm), a twenty-speed (20×) (4,400 rpm), and further a twenty-four-speed (24×) (5,400 rpm), for example, comparing to the standard rotation speed (220 rpm) of the initial optical disk apparatus. And, further more recently, that having a forty-speed is on the development thereof.
By the way, accompanying an increase of the rotation speed of the disk, as was mentioned above, wind sounds generated when the disk rotates (i.e., noises when the disk cuts an air around) comes to be large, and this is the main factor for a source of generating noises. However, conventionally, for the purpose of reducing the noises of the wind sounds due to the rotation speed of the disk mentioned above, it is already proposed to form a portion(s) (i.e., a step-like portion(s)) on a drawer frame (i.e., a tray), being restricted in the height from a flat portion thereof, to be equal or lower than that nearly equal to the upper surface of the disk, which is disposed on a predetermined position in the circular area or region, in the following Patent Document 1, for example.
Also, with the following Patent Document 2, for example, there is already proposed the structures of enlarging the distance from a center of a spindle up to a frond-end sidewall of the said tray, to be larger than a predetermined value (2.75 mm), in the tray of the optical disk reproducing apparatus, for the purpose of preventing flatter, which exerts ill influences upon the recording/reproducing when the disk rotates at high speed.
Japanese Patent Laying-Open No. 2002-25240 (2002); and
Japanese Patent Laying-Open No. 2004-199861 (2004).
However, according to the optical disk apparatus, relating to the conventional arts, in particular, the former thereof, though forming the step-like portion on the periphery of the drawer frame, there are still caused flows of air having a large flow velocity, within a gap defined between an upper end surface portion of step-like portion and the tip portion of the disk rotating at high speed, and therefore it is impossible to obtain an effect of fully reducing the noises, necessarily. Also, further in a case when forming the step-like portion on the periphery of the drawer frame, there is a drawback that this deteriorates a loading property, in particular, when loading the optical disk at the central portion thereof. Thus, with such the step(s), the optical disk to be loaded is caught thereon, on the way of the loading, or in a case when forming the step-like portion, approximately covering all over the periphery portion, it is difficult for the optical disk to be guided to the predetermined position, even if forming a fragment of a stopper, for example. Furthermore, although the drawer frame having such step-like portion is made through a molding process of resin, ordinarily, however there can be also pointed out the following drawbacks; i.e., a die for that comes to be complex, a working process increases the number thereof, and it results into a reason of increasing the costs of the apparatus as a whole. Also, within the optical disk reproducing apparatus relating to the conventional arts, in particular, the latter thereof, no consideration is made on the structures for reducing the noises therein, and for that reason, it never discloses anything of the detailed structure for that purpose therein.